移民在異國安頓後，經常匯錢返鄉接濟親人。在中間所得國家中，印度從本國僑民獲得的返鄉匯款最多，一年達到710億元，中國有602億元，菲律賓有261億元。世界銀行定義的「中間所得國家」，是人均所得在1036元至1萬2605元之間的國家。

彭博新聞社報導說，17日公布的這份研究報告顯示，到高所得國家的國際移民愈來愈多，前往美國的移民更遠超過其他國家，占所有國際移民的五分之一，返鄉匯款也最多，去年達到1233億元。

現在的國際移民約有七成住在人均所得1萬2616元以上的較高所得國家，總數大約1億6000萬人。研究報告強烈顯示經濟情況對移民流動扮演重要角色，尤其北美和歐洲等地的高所得國家，對印度和墨西哥等地的移民吸引力愈來愈大，因為他們主要是想追求經濟機會。

美國和俄國是國際移民最多的國家，1990年排名第六的德國也上升到第三名。

1990年美國有2300萬移民，現已增加到4500萬人。排名第二的俄國，1990和2013年移民總數維持大約1100萬人。

現在的國際移民也日益來自「中間所得國家」，約有六成國際移民生在這些國家，總數有1億3500萬人。

美國雖然最近幾十年移民急遽增加，可是外國出生人口仍然只占全國人口14%，遠低於澳洲的28%和加拿大的21%。

美國的移民來源也愈來愈集中，現在美國的外國移民有55%來自拉丁美洲和加勒比海國家。

   Global Immigrants Send $500 Billion Back Home    

Photographer：John Moore/Getty Images

International migrants are sending more than $500 billion back to family members each year, almost triple the figure since 2000, providing a major economic boost to less-affluent nations, a Pew Research Center study shows.

A rising share of migrants live in high-income countries, including the U.S., by far the most common destination, according to the report released yesterday. The U.S. has a fifth of the world’s migrants, up from almost a sixth in 1990. It’s also the largest source of payments, sending $123.3 billion in 2012, the Pew analysis of World Bank data shows.

Seven in 10 international migrants -- about 160 million people -- live in higher-income nations, those with the equivalent of an average per capita income of $12,616 or higher, up from 57 percent in 1990, the analysis shows.

“Migrants are moving out, but they are also moving up,”said Phillip Connor, one of the report’s authors. “It’s not necessarily people from the lowest-income country groups that have been more likely to move in the last quarter-century. It’s more of that middle tier. There’s this movement from middle to high.”

The report found that high-income countries, many in North America and Europe, may appear increasingly attractive to migrants from places such as India and Mexico, whose principal reason for moving is to pursue economic opportunity.

The analysis, which comes as legislation to revise U.S. immigration policy is stalled in Congress, underscores the central role economic conditions play in the flow of immigrants.

U.S., Russia

The report defines migrants as those living for one year or longer in a country other than where they were born. Many foreign workers and international students are counted under that definition, as are refugees and undocumented immigrants.

The U.S. and Russia easily remain the top two destinations, while Germany has risen to third from sixth in 1990.

The number of immigrants in the U.S. doubled to 46 million in 2013 from 23 million in 1990. During that time, no other country has come close to the number of foreign-born people living within its borders. Second-ranked Russia had about 11 million immigrants in both 1990 and 2013.

Once they move across borders, migrants often send money, known as remittances, back to families in their countries of origin. Remittances account for an average of 8 percent of the gross domestic product of low-income nations, Pew said, basing its analysis on World Bank data.

Immigrants increasingly were born in what the World Bank designates as “middle income” countries, where per capita annual income is between $1,036 and $12,615. About six-in-10, or 135 million, were born in such countries, compared with less than half of all migrants in 1990.

India, China

Among the middle-income countries, India, with $71 billion, China, $60.2 billion, and the Philippines, $26.1 billion, received the most annual remittances.

Even with the growth in recent decades, the foreign born as a share of the total U.S. population is considerably lower than in many other nations. About 14 percent of the country’s population in 2013 was foreign born, a smaller share than inAustralia, with 28 percent, and Canada, 21 percent, Pew said.

The proportion of migrants in the U.S. is also substantially lower than in some countries in the Persian Gulf, where the vast majorities of their populations are foreign-born workers. Citing United Nations’ data, Pew said 84 percent of the population in the United Arab Emirates is foreign born, while 74 percent in Qatar are.

In the U.S., the regional origins of immigrants have become more concentrated in recent decades, the study said. Fifty-five percent of all migrants living in the U.S. are from Latin American and Caribbean countries, up from 47 percent in 1990, Pew said.

Prospects for passing immigration-law changes have languished in Congress amid partisan battles over spending and health care. The House Republican majority has rejected a comprehensive plan passed June 27 by the Democratic-controlled Senate.

The chances for enacting a law by year’s end dimmed after House leaders said they would consider a series of bills instead of one comprehensive measure.